After doing this exercise, it occurs to me that doing the averaging is a lot of work for very little change. In other words, a +1 on the roll isn't that huge of a difference, so it's probably not worth taking the time to compute things (figure out the average, like I was suggesting in the earlier post).

It's probably just better to go with the RAW/majority (which in this case would be a lower #/easier terrain), and then maybe add a +1 if there's a significant challenge (i.e., much more dangerous terrain along the journey).

Adventure Summaries for my long-running group (currently playing through The Darkening of Mirkwood/Mirkwood Campaign), and the Tale of Years for a second, lower-level group (in the same campaign).

I would not agree. It's not only +1 to the roll (if you meant number of events), its a probably increasing DC of all challenges during Journey by 1-2 which is huge difference.

Figuring out average is in fact very easy task. In this example you're crossing Easy (1), Moderate (2) and Daunting (5) Terrain. Adding them up and dividing by 3 gives us a Peril Rating 2,6, rounded up to 3. Done.

Thror's idea to rolling for events and placing them in desired Regions is a little more time-consuming (you need to roll all of them and decide where they will occur) and a bit arbitrary, but worth considering. It certainly enforces the mood of certain Regions.

I would not agree. It's not only +1 to the roll (if you meant number of events), its a probably increasing DC of all challenges during Journey by 1-2 which is huge difference.

Figuring out average is in fact very easy task. In this example you're crossing Easy (1), Moderate (2) and Daunting (5) Terrain. Adding them up and dividing by 3 gives us a Peril Rating 2,6, rounded up to 3. Done.

Thror's idea to rolling for events and placing them in desired Regions is a little more time-consuming (you need to roll all of them and decide where they will occur) and a bit arbitrary, but worth considering. It certainly enforces the mood of certain Regions.

I don't think it's much more work, really.

You're going to calculate the journey anyway. You're going to calculate how many Events. You'd probably roll the individual Events as well, so you can place them where they'd be most appropriate.

In the "Rivendell to Beorn's House" journey that has been used as the example, There are three regions: Rivendell (Moderate [Peril 2]), High Pass (Daunting [Peril 5]), and the West Middle Vales (Easy [Peril 1]).

As the GM, I roll a 'meeting on the road' type Event; an 'enemy encounter' Event; and an 'environmental hazard' Event. I can now plan my player's journey. I decide to have the 'meeting on the road' in Rivendell region (Dwarven merchants coming back from Erebor); the 'environmental hazard' in the High Pass (I choose a landslide hazard test); and finally the 'enemy encounter' are Wargs in the foothills.

This way the challenges of the High Pass (DC12+5) are tough, as they should be.

Your method certainly supports more "cinematic" approach. You can plan events and match them with desired terrain.
The only downside of this method is that certain terrains generate more events, but you can always roll for extra event for more demanding terrain.
I would also prefer to play events in the same order they were rolled, to have a stronger feeling of randomness and "blind luck" (good or bad), but it's only my preference.

I would also prefer to play events in the same order they were rolled, to have a stronger feeling of randomness and "blind luck" (good or bad), but it's only my preference.

And you totally do that. The nice thing is that that Event (whatever it is) will be noticeably more difficult in Mirkwood, than say in the East Middle Vale [where Beorn lives]). Which is the point, and seems appropriate. Otherwise, why is it harder to start a fire in Beorn's neck of the woods, just because you were in Mirkwood a few days ago?

Perhaps that +1 will have more impact for lower level characters, but I don't think it changes much in my game. Even adding that +1 to the TNs will have quite minimal impact.

Our group has numbers so high that they usually end up on the highest ends of the charts, so on the Embarkation Table, for example, they usually get a '12 or more'.

Our highest level character, who often serves as the Guide, has a 17 for his Survival (plus 1d20). The other Mirkwood Elf has a 28 Passive Perception, and if he rolls active Perception, he's rolling an 18 + 1d20, but also at Advantage (he wears a ring with a Blessing to Perception).

So at least for us, if I were to just simply add in a +1, it wouldn't even matter that much. But I suppose with much less proficient characters, it could have a much bigger impact.

Your method of averaging is much quicker than what I was doing. I was figuring out a true average, based on the amount of hexes travelled through at each difficulty (rather than just averaging it by 3). I agree, if you just average by 3, then that's pretty quick and simple, and wouldn't be that difficult to do.

Adventure Summaries for my long-running group (currently playing through The Darkening of Mirkwood/Mirkwood Campaign), and the Tale of Years for a second, lower-level group (in the same campaign).

After some discussion with zedturtle, he helped me realize that I'd made an error on one of my characters (from an earlier post). Our amazingly perceptive Mirkwood Elf still has an otherworldly 28 passive Perception, but his active Perception should only be a 13 (with advantage), rather than an 18.

A big thanks to zed for the help; now I least have a chance of him not finding something he's looking for, though the days of any enemy successfully sneaking up on the party are very likely over.

Adventure Summaries for my long-running group (currently playing through The Darkening of Mirkwood/Mirkwood Campaign), and the Tale of Years for a second, lower-level group (in the same campaign).

Our highest level character, who often serves as the Guide, has a 17 for his Survival (plus 1d20).

Correct me if I am wrong, but for purpose of Embarkation roll you cannot subtract from Peril Rating more than 8-9 (Hero's proficiency bonus [max +6] and half of his Wisdom bonus (+2 or +3 [Players Guide do not specifies if this value is rounded up or down] with Wisdom 20 ].
It means, that travelling through the Daunting Terrain (in winter ) you roll for Embarkation with max bonus +2 (+3 if you're rounding half of the Wisdom bonus up). With d12 there is still room for results less than "12 or more" - even in lighter terrain

Ummm... I am not missing it at all.
Path of Wisdom: Your proficiency bonus is doubled for any ability checks [...]
Expertise: Your proficiency bonus is doubled for any ability checks [...]
Known Lands: When you make Intelligence or Wisdom check [...] your proficiency bonus is doubled
etc.

All those features gives you bonus when you're making ability checks - i.e. when you're rolling d20 and adding or subtracting ability and sometimes proficiency modifiers (p.7 of PHB 5th ed.).
Calculating Embarkation roll bonus/penalty is not a check. It's... calculating a Embarkation roll bonus/penalty